Steam turbine plant, and method of operating a steam turbine plant

ABSTRACT

In a steam turbine plant having a vacuum pumping configuration which has a jet pump and a liquid ring pump disposed in series one after the other, steam collecting in the plant, preferably mixed with air, is used as a motive fluid for the jet pump. As a result, the downstream liquid ring pump can be dimensioned so as to be comparatively small. The vacuum pumping configuration is preferably configured as a central vacuum pumping system for the steam turbine plant and serves to deaerate a multiplicity of plant components.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is a continuation of copending InternationalApplication No. PCT/DE01/03673, filed Sep. 24, 2001, which designatedthe United States and was not published in English.

BACKGROUND OF THE INVENTION

[0002] Field of the Invention

[0003] The invention relates to a steam turbine plant having a vacuumpumping configuration that has a jet pump and a liquid ring pumpdisposed in series one after the other. The invention also relates to amethod of operating a steam turbine plant, in which a plant component isdeaerated by use of a vacuum pumping configuration which has a jet pumpand a liquid ring pump disposed in series one after the other.

[0004] In a steam turbine plant, for example in the field of powergeneration, a main turbine plant having a plurality of turbine stages isprovided as a rule in order to utilize as effectively as possible theenergy content of the steam provided. As a rule, high-capacity steamturbine plants have a high-pressure stage, an intermediate-pressurestage and a low-pressure stage, steam heated in a boiler is fed to thehigh-pressure stage and expands in the direction of the low-pressurestage. At the end, the low-pressure stage has a vacuum in the order ofmagnitude of between 18 mbar and 80 mbar. The steam discharging from thelow-pressure stage is fed to a condenser and is condensed there.

[0005] The gas quantity collecting during the condensing in thecondenser must be drawn off from the latter. Provided for this purposeis a vacuum pumping configuration, which, on account of the low finalpressure at the low-pressure stage, must reach a vacuum of, for example,≦18 mbar on the suction side. On account of the steam quantity whichcollects in the steam turbine plant and which is large as a rule, thevacuum pumping configuration must be configured for drawing off a largegas quantity of a delivery gas from the condenser in order to deaeratethe latter.

[0006] Furthermore, in a steam turbine plant for a large power plant, anauxiliary turbine for a feed water supply to the boiler is normallyprovided, the auxiliary turbine having, for example, an output of 20 MW,compared with an output of the main turbine plant of about 1 GW. Acondenser, which must be deaerated, is likewise assigned to theauxiliary turbine.

[0007] As a rule, the respective condenser contains a tube system, towhich the steam to be condensed is admitted from the turbine. The steamis cooled by water, which is fed to the condenser via a “water chamber”.In order to maintain the operability of the condenser, the water chambermust also be deaerated. On account of the different requirements for thedeaerating capacity with regard to the condenser for the low-pressurestage, for the auxiliary turbine, and with regard to the water chamberof the condenser, a separate vacuum pumping configuration is currentlyprovided for each of the three subsystems.

[0008] For deaerating a condenser of a steam turbine, British Patent GB1 542 483 discloses a vacuum pumping configuration in which a jet pumpand a liquid ring pump are provided in series one after the other. Themotive fluid provided for the jet pump is air. The vacuum to be achievedis improved by connecting the jet pump upstream of the liquid ring pump.A vacuum of about 50 mbar can typically be achieved with a liquid ringpump. A vacuum of up to <15 mbar can be achieved with the entire systemby connecting a jet pump upstream.

[0009] In the system formed of the jet pump and the liquid ring pumpthere is generally the problem that the liquid ring pump has to beconfigured for both the quantity of the actual delivery gas to be drawnoff plus the quantity of the motive fluid for the jet pump. In thiscase, the requisite quantity of motive air for an air-operated jet pumpis many times higher than the quantity of delivery gas to be drawn offfrom the condenser. For example, in order to compress a delivery-gasmass flow from a condenser, formed of a mixture of about 15 kg/h of airand 35 kg/h of steam, from about 40 mbar to 125 mbar by the jet pump, aworking-air mass flow of about 200 kg/h is required. On account of thishigh air proportion, the liquid ring pump is to be configured for dryair as the delivery gas. This reduces the capacity of the liquid ringpump, compared with moist air as the delivery gas.

[0010] A liquid ring pump and its operating principle can be seen, forexample, from the Siemens brochure titled “ELMO-L2BL1-luftgekühlt,õlfrei: die neue Generation von Vakuumpumpen” [ELMO-L2BL1—Air-Cooled,Oil-Free: The New Generation Of Vacuum Pumps], SiemensAktiengesellschaft Germany, 12/98, Order No.: E20001-P782-A208, or fromthe Internet at http:\\www.ad.siemens.de/elmo (status August 2000). Theliquid ring pump described has an impeller sitting eccentrically in ahousing. By the impeller rotation, an operating medium, as a rule water,forms a water ring revolving with the impeller in the housing. Onaccount of the eccentric configuration of the impeller, sectional spacesof different size form between the impeller hub and the water ringrevolving with the impeller, and the medium to be pumped is compressedin the sectional spaces.

[0011] Furthermore, the combination of a jet pump with a downstreamliquid ring pump has been disclosed, for example, by Published, EuropeanPatent Application EP 0 088 226 A2, U.S. Pat. No. 4,484,457 A andPublished, Non-Prosecuted German Patent Application DE 29 13 960 A1.According to EP 0 088 226 A2, the liquid ring pump is operated with oilas the operating medium, which is heated up to a temperature of about130° C. In order to utilize the energy stored in the oil, provision ismade to evaporate water via a heat exchanger and to feed the steam asthe motive fluid to the jet pump. A separate supply of motive fluid istherefore not necessary in the system. However, the system is restrictedto oil-operated liquid ring pumps, in which the oil can be heated totemperatures above 100° C. As a rule, the liquid ring pumps are operatedwith water, which is normally heated up to about 35° C. at most, as canbe seen from the above-mentioned Siemens brochure.

[0012] The interaction of a liquid ring pump with a turbine has alsobeen disclosed by U.S. Pat. No. 4,484,457, which claims the samepriority as EP 0 088 226 A2.

[0013] According to Published, Non-Prosecuted German Patent ApplicationDE 29 13 960 A1, air is fed as motive fluid to the jet pump from aseparator assigned to the liquid ring pump. In this case, the airextracted from the separator is dehydrated so that air that is as dry aspossible is fed to the jet pump.

[0014] A jet pump to which steam is fed as the motive fluid has beendisclosed, for example, by U.S. Pat. No. 3,481,529. A liquid ring pumpis connected directly downstream of the jet pump.

SUMMARY OF THE INVENTION

[0015] It is accordingly an object of the invention to provide a steamturbine plant, and a method of operating the steam turbine plant thatovercome the above-mentioned disadvantages of the prior art devices andmethods of this general type, which permits a cost-effective operationof a steam turbine plant in a simple installation.

[0016] With the foregoing and other objects in view there is provided,in accordance with the invention, a steam turbine plant. The plantcontains a vacuum pumping configuration having a jet pump and a liquidring pump disposed in series one after another, a sealing steam circuitfor a turbine seal, and a steam line connected to the sealing-steamcircuit and provided for feeding steam, collecting in the steam turbineplant, as a motive fluid for the jet pump. The steam line connected tothe jet pump.

[0017] The object is achieved according to the invention by a steamturbine plant having a vacuum pumping configuration which has a jet pumpand a liquid ring pump disposed in series one after the other, a steamline for feeding steam, collecting in the plant, as the motive fluid forthe jet pump being connected to the jet pump.

[0018] The steam used in this case is in particular excess steam inorder not to impair the efficiency of the steam turbine plant. The useof steam as the motive fluid has the decisive advantage that, as aresult, the quantity of noncondensable motive fluid required is markedlyreduced compared with the motive air normally used. As a result, it ispossible to configure the liquid ring pump disposed downstream of thejet pump for markedly smaller mass flows, so that considerable costsavings can thereby be achieved. This is because, through the use ofsteam or of steam/air mixture under atmospheric pressure as the motivefluid, the power requirement with regard to the mass flow to bedelivered by the liquid ring pump decreases by about 40-50%, since thevaporous mass proportion in the liquid ring pump condenses and does nothave to be compressed to atmospheric pressure.

[0019] The steam line via which steam is fed as the motive fluid to thejet pump is expediently connected to a sealing-steam circuit for aturbine-shaft sealing system.

[0020] To seal the rotating turbine shaft, a labyrinth seal, throughwhich “sealing steam” is directed, is provided as a rule. After leavingthe turbine seal, the sealing steam is also referred to as low-tensionsteam. The low-tension steam is a “waste product” collecting in thesteam turbine plant and is therefore especially suitable for use asmotive fluid under atmospheric pressure without impairing the efficiencyof the steam turbine plant.

[0021] In addition, the feeding of the low-tension steam to the vacuumpumping configuration also has the decisive advantage that thelow-tension steam—due to the principle of the liquid ringpump—condenses. The condensing system, normally provided in a steamturbine plant, for the low-tension steam is therefore not necessary. Asa result, investment costs can be saved, and in addition the requisiteinstallation requirement is reduced compared with conventional steamturbine plants.

[0022] A gas line for admixing air for forming a steam/air mixture asmotive fluid for the jet pump is expediently connected to the steamline. This results in especially efficient operation for the jet pump.In particular, an approximately uniform mass flow distribution betweenair and steam is set for the mixture. In addition, the admixing of airhas the advantage that the requisite quantity of motive fluid can be setin a simple manner, in particular when the quantity of low-tension steamis limited, so that the steam quantity alone is not sufficient as themotive fluid.

[0023] In this case, the gas line, with its further end, is expedientlyconnected on the pressure side to the liquid ring pump and in particularto a separator assigned to the liquid ring pump. The air compressed toatmospheric pressure by the liquid ring pump is therefore also used asthe motive fluid. This has the advantage that a separate compressor forfeeding the jet pump is not required.

[0024] According to an expedient configuration, the vacuum pumpingconfiguration is connected to a condenser via a first deaerating linefor deaerating the condenser, which is provided for condensing processsteam discharging from a steam turbine, in particular from alow-pressure part of a steam turbine.

[0025] The vacuum pumping configuration is at the same time preferablyconnected via a second deaerating line to a second condenser, which isassigned to an auxiliary turbine. Thus preferably both the condenser ofthe main turbine and that of the auxiliary turbine are deaerated via thesame vacuum pumping configuration. A plurality of vacuum pumpingconfigurations assigned to the individual condensers are therefore notnecessary.

[0026] As a rule, the condenser, for a cooling liquid, has a waterchamber, which, in order to deaerate it, is preferably connected to thevacuum pumping configuration via a third deaerating line.

[0027] A uniform, central vacuum pumping system in the form of thevacuum pumping configuration is therefore provided, and the vacuumpumping system provides a vacuum for a multiplicity of components in thesteam turbine plant. As a result, the installation cost and also themaintenance cost with regard to the vacuum pumping system are markedlyreduced compared with a multiplicity of decentral vacuum pumpingsystems.

[0028] To deaerate the water chamber, the third deaerating line ispreferably connected to an additional port of the liquid ring pump. Viathe additional port, saturated water-chamber air being emitted from thecooling water is drawn off from the water chamber. This has theessential advantage that the quantity of saturated air drawn off fromthe water chamber is fed separately to the liquid ring pump and is notadded to the delivery-gas quantity drawn off from the two condensers.

[0029] In this case, the additional port is expediently disposed betweena suction connection and a pressure connection of the liquid ring pumpand is connected to a working or compression space forming duringoperation. The third deaerating line therefore feeds the saturated airfrom the water chamber to the liquid ring pump in an intermediate regionbetween the suction connection and the pressure connection. In thisregion, a sufficient vacuum for deaerating the water chamber is stillprovided by the liquid ring pump. At the same time, however, the feedingat this point does not lead to an increase, or only leads to animperceptible increase, in the power requirement of the liquid ringpump. Delivery capacity is provided by the liquid ring pump via thecavitation protection port virtually “for nothing”. When the thirddeaerating line is disposed at the additional port, the liquid ring pumptherefore does not need to be of larger dimensions.

[0030] The use of such an additional port as an additional suctionconnection is a basic principle here and is generally suitable for allliquid ring pumps and is not restricted to application in a steamturbine plant. A liquid ring pump having such an additional port is alsosuitable, for example, for deaerating a screen part on papermakingmachines in the paper industry.

[0031] In general, such a liquid ring pump is suitable for use in thefield of papermaking. By suitable placing of the additional port betweenthe suction connection and the pressure connection, and by the selectionof the diameter of the additional port, the suction capacity can at thesame time be varied within certain limits both with regard to thevolumetric quantity and with regard to the vacuum to be achieved.

[0032] Furthermore, the object is achieved according to the invention bya method of operating a steam turbine plant, in which a plant componentis deaerated by a vacuum pumping configuration which has a jet pump anda liquid ring pump disposed in series one after the other, steamcollecting in the steam turbine plant, in particular excess steam, beingfed as motive fluid to the jet pump.

[0033] The advantages and preferred configurations recited with regardto the steam turbine plant can accordingly be applied to the method.

[0034] Other features which are considered as characteristic for theinvention are set forth in the appended claims.

[0035] Although the invention is illustrated and described herein asembodied in a steam turbine plant, and a method of operating a steamturbine plant, it is nevertheless not intended to be limited to thedetails shown, since various modifications and structural changes may bemade therein without departing from the spirit of the invention andwithin the scope and range of equivalents of the claims.

[0036] The construction and method of operation of the invention,however, together with additional objects and advantages thereof will bebest understood from the following description of specific embodimentswhen read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0037]FIG. 1 is an illustration of a steam turbine plant according tothe invention; and

[0038]FIG. 2 is a diagrammatic, sectional view through a liquid ringpump.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] Referring now to the figures of the drawing in detail and first,particularly, to FIG. 1 thereof, there is shown a steam turbine plant 2that has a steam turbine 4 which in particular is a low-pressure stageof a, for example, 3-stage main turbine plant. Such a multistage mainturbine plant is used, for example, in power plants for the generationof power with an output within the gigawatt range. On an output side,the steam turbine 4 has a vacuum, which in a low-pressure stage istypically within a range of between 18 mbar and 80 mbar. Process steam Pfed to the steam turbine 4 leaves the latter via output lines 6 and isfed to a first condenser 8. The process steam P is condensed in thecondenser 8, the condensate being discharged via a discharge line 10 andfed again as feed water to a boiler (not shown in any more detail).

[0040] During the condensing, a gas/steam mixture designated as deliverygas F collects in the first condenser 8 and is drawn off via a firstdeaerating line 12 by a vacuum pumping configuration 14.

[0041] Furthermore, the steam turbine plant 2 has an auxiliary turbine16 that is configured in a similar manner to the steam turbine 4 but fora markedly lower output. The auxiliary turbine 16 is used in particularfor driving a feed water pump and typically has an output of about 20MW. In a similar manner to the steam turbine 4, a second condenser 18 isassigned to the auxiliary turbine 16, the process steam P fed to theauxiliary turbine 16 being condensed in the second condenser 18. In asimilar manner to the first condenser 8, the condensate is dischargedvia a discharge line 10. To deaerate the second condenser 18, a seconddeaerating line 20 is provided, which is likewise connected to thevacuum pumping configuration 14. Via the second deaerating line 20, agas/steam mixture is likewise pumped out of the second condenser 18 asthe delivery gas F. In this case, the first deaerating line 12 opensinto the second deaerating line 20.

[0042] The two condensers 8, 18 preferably have water as a coolingmedium, which is stored in a water chamber 22 of the respectivecondenser 8, 18. During operation of the condensers 8, 18, an aircushion forms in the respective water chamber 22. To deaerate at leastthe water chamber 22 of the first condenser 8, a third deaerating line24 is provided, which likewise leads to the vacuum pumping configuration14. In this case, the saturated air being emitted from the cooling wateris drawn off from the water chamber 22 and is designated aswater-chamber air WL.

[0043] The vacuum pumping configuration 14 contains a jet pump 26 and aliquid ring pump 28 disposed downstream of the jet pump 26 in thedirection of flow. To this end, the second deaerating line 20 isconnected to a suction region 27 of the jet pump 26, and the latter isconnected on the output side to a suction connection 30 of the liquidring pump 28. The delivery gas F from the two condensers 8, 18 is thusfirst of all precompressed by the jet pump 26. To this end, the jet pump26 is operated with a motive fluid T that is fed externally and mixeswith the delivery gas F. The pressure in the first condenser 8 and inthe second condenser 18 is typically within a range which correspondsapproximately to the output pressure of the steam turbine 4 and of theauxiliary turbine 16, respectively. There is therefore a vacuum within arange of between 18 and 80 mbar in both condensers 8, 18. Consequentlythe delivery gas F likewise has this vacuum. It is compressedapproximately by the factor 3 in the jet pump 26 and then further up toambient pressure in the liquid ring pump and is expelled via a pressureconnection 34.

[0044] Furthermore, the liquid ring pump 28, between the suctionconnection 30 and the pressure connection 34, has an additional port 35,to which the third deaerating line 24 is connected. In this case, theadditional port 35 is disposed between an intake slot 70 and a pressureslot 72 (see FIG. 2) in non-illustrated “control disks” of the liquidring pump 28. Due to the operating principle of the liquid ring pump 28,the pump mixture of the delivery gas F and the motive fluid T fed viathe suction connection 30 mixes with the operating medium of the liquidring pump 28. In this case, the operating medium is water W. The lattertogether with condensate possibly collecting from the pump mixture isseparated from air L in a separator 38. The water W is fed again to theliquid ring pump 28 via a heat exchanger 40. The air L is fed as themotive fluid T to the jet pump 26 via a gas line 42, in which a valve 44is connected. Excess air L is given off to the environment from thevacuum pumping configuration 14 via an exhaust-air line 46.

[0045] It is essential that, in addition to the air L, steam D is alsofed as the motive fluid T to the jet pump 26 via a steam line 48. Afurther valve 44 is connected in the steam line 48. In this case, thesteam line 48 is connected to a sealing-steam circuit 50 in whichsealing steam S is directed through a number of turbine seals 52. Theturbine seals 52 in this case are assigned to the steam turbine 4 and tothe auxiliary turbine 16 and are configured as labyrinth seals in orderto seal off a rotating shaft of the turbines 4, 16 from the environment.After flowing through the turbine seals 52, the sealing steam is alsoreferred to as low-tension steam. The steam D is fed as the motive fluidT to the jet pump 26. The motive fluid T is therefore a steam/airmixture, it being possible for the respective proportions of the steam Dand of the air L to be set via the two valves 44. An equal distributionbetween steam D and air L is preferably set. If an adequate steamquantity is available, steam D may also be used exclusively as themotive fluid T. Since the low-tension steam is excess steam collectingin the steam turbine plant 2, the overall efficiency of the steamturbine plant 2 is not impaired by use of the low-tension steam as themotive fluid T. In addition to the use of the low-tension steam, othertypes of steam collecting in the steam turbine plant are also suitable.For example, the steam collecting in the sealing-steam system forcontrol purposes and normally discarded in one of the condensers 8, 18is suitable.

[0046] The operating principle of the liquid ring pump 28, which has animpeller 64 mounted eccentrically in the housing 62 of the liquid ringpump 28, can be seen with reference to the schematic representation of across section through the liquid ring pump 28 according to FIG. 2.During operation, the water W forms a liquid ring 66 which revolves withthe impeller 64, so that sectional spaces 68 of different volume formbetween the individual spokes of the impeller 64 and the liquid ring 66.An intake slot via which the medium to be drawn in is drawn in via thesuction connection 30 is provided in the housing 62 at the end face atthe position identified by reference numeral 70. Due to the eccentricconfiguration, the medium to be pumped is compressed in the course ofthe revolution of the impeller 64 and is expelled via a pressure slot tothe pressure connection 34 at the position identified by referencenumeral 72.

[0047] The additional port 35 is disposed between the intake slot 70 andthe pressure slot 72 in the housing 62 and is connected to the workingspace, which is formed by the individual sectional spaces 68. Dependingon the position of the additional port 35, the suction capacity,prevailing at this position, of the liquid ring pump 28 varies withregard to both the prevailing vacuum and the delivery quantity. Inaddition, the suction capacity can be varied by selection of thediameter of the additional port 35.

[0048] Although the vacuum at the additional port 35 is above the vacuumapplied at the suction connection 30, it is sufficiently low in order topermit deaeration of the water chamber 22. The volumetric suctioncapacity for deaerating the water chamber 22 is also sufficiently high.Since the third deaerating line 24 is not connected to the suctionconnection 30, the liquid ring pump 28 is not additionally loaded by theadditionally fed gas mixture G or is only barely subjected to additionalloading by the latter. Slightly greater dimensioning, possibly necessarydue to the connection of the third deaerating line 24, of the liquidring pump 28 is in any case more favorable compared with a separatepumping system for the deaeration of the water chamber 22.

[0049] A steam turbine plant of such a configuration with a uniform,central vacuum pumping configuration 14 has essentially the followingadvantages:

[0050] a. On account of the use of steam D and air L as the motive fluidT for the jet pump 26—compared with the use exclusively of air L as themotive fluid T—the liquid ring pump 28 can be configured to be markedlysmaller, since the steam D condenses in the liquid ring pump, and onlythe air proportion has to be compressed to atmospheric pressure.

[0051] b. The low-tension steam collecting in the sealing-steam circuit50 is preferably completely directed via the vacuum pumpingconfiguration 14. In this case, it is not absolutely necessary for theentire quantity of the low-tension steam to be used as the motive fluidT for the jet pump 26. By the feeding of the low-tension steam to theliquid ring pump 28 having the associated separator 38, the low-tensionsteam is condensed, so that a separate condensing system is not requiredfor the low-tension steam.

[0052] c. For all the plant components that have to be connected to avacuum system, the vacuum pumping configuration 14 is provided as acentral vacuum system. This makes possible a simple and cost-effectiveinstallation. In particular, it is not necessary to install a pluralityof decentral vacuum pumping systems.

[0053] d. Due to the connection of the third deaerating line 24 to theadditional port 35, a suction capacity provided virtually “for nothing”by the liquid ring pump 28 is utilized without the liquid ring pump 28having to be of larger dimensions due to the connection of this thirddeaerating line 24.

We claim:
 1. A steam turbine plant, comprising: a vacuum pumpingconfiguration having a jet pump and a liquid ring pump disposed inseries one after another; a sealing steam circuit for a turbine seal;and a steam line connected to said sealing-steam circuit and providedfor feeding steam, collecting in the steam turbine plant, as a motivefluid for said jet pump, said steam line connected to said jet pump. 2.The plant according to claim 1, further comprising a gas line connectedto said steam line, said gas line admixing air to the steam resulting ina steam/air mixture as the motive fluid.
 3. The plant according to claim2, wherein said liquid ring pump has a pressure side and said gas lineis also connected on said pressure side to said liquid ring pump.
 4. Theplant according to claim 1, further comprising: a steam turbine; acondenser disposed downstream of said steam turbine and condensingprocess steam discharging from said steam turbine; and a dearating lineconnecting said condenser to said vacuum pumping configuration, saiddearating line provided for deaerating said condenser.
 5. The plantaccording to claim 4, further comproising: an auxiliary turbine; afurther condenser disposed downstream of said auxiliary turbine; and afurther dearating line connecting said further condenser to said vacuumpumping configuration.
 6. The plant according to claim 4, furthercomprising an additional dearating line, said condenser, for a coolingliquid, has a water chamber, which, in order to deaerate said waterchamber, said water chamber is connected to said vacuum pumpingconfiguration by said additional deaerating line.
 7. The plant accordingto claim 6, wherein said liquid ring pump has an additional portconnected to said additional deaerating line.
 8. The plant according toclaim 7, wherein said liquid ring pump has a housing with a suctionconnection and a pressure connection, said additional port is disposedbetween said suction connection and said pressure connection and isconnected to a working space forming during operation.
 9. The plantaccording to claim 3, further comprising a separator connected betweensaid pressure side of said liquid ring pump and said gas line.
 10. Theplant according to claim 4, wherein said steam turbine has alow-pressure part and said condenser is provided for condensing theprocess steam discharging from said low-pressure part.
 11. A method ofoperating a steam turbine plant, which comprises the steps of:deaerating a plant component using a vacuum pumping configuration havinga jet pump and a liquid ring pump disposed in series one after another;feeding steam collecting in the steam turbine plant as sealing steam fora turbine seal as a motive fluid to the jet pump.
 12. The methodaccording to claim 11, which further comprises forming the motive fluidas a steam/air mixture.
 13. The method according to claim 12, whichfurther comprises setting a ratio of steam and air in the steam/airmixture to be approximately equal.
 14. The method according to claim 11,which further comprises condensing the sealing steam in the vacuumpumping configuration.
 15. The method according to claim 11, whichfurther comprises deaerating a condenser of a steam turbine.
 16. Themethod according to claim 15, which further comprises deaerating a waterchamber of the condenser.
 17. The method according to claim 16, whichfurther comprises for deaerating the water chamber, drawing offsaturated water-chamber air collecting in the water chamber through anadditional port in the liquid ring pump.